Audible currently have two free short Christmas listens I do not know if it's restricted to current subscribers or not but I don't think it is. However Grinch appears to be for US accounts only and Sherlock is for all. Merry Christmas :)
How the Grinch Stole Christmas by Dr Seuss narrated by Walter Matthau http://www.audible.com/pd?asin=B00ALYCA9O
The Grinch, whose heart is two sizes too small, hates Whoville's holiday celebrations, and plans to steal all the presents to prevent Christmas from coming. To his amazement, Christmas comes anyway, and the Grinch discovers the true meaning of the holiday.
The Adventure of the Blue Carbuncle by Athor Conan Doyle Narrated by Alan Cumming http://www.audible.com/pd?asin=B00AJ2VYRC
Sir Arthur Conan Doyle’s Yuletide whodunit "The Adventure of the Blue Carbuncle". In this holiday-themed short story, Sherlock Holmes and his trusty sidekick, Dr. Watson, follow the trail of a lost hat and a Christmas goose through the streets of London and into a rapidly expanding mystery. And, since a great story calls for a great voice, we’ve brought in Emmy Award nominee Alan Cumming (TV's The Good Wife), a past Audie Award winner for Best Male Narrator and one of our very favourite narrators
Grinch indeed - "We're sorry. Due to publishing rights restrictions, we are not authorized to sell this item in the country where you live."
Sherlock Holmes works fine.